KR0127877B1 - Method for wheels - Google Patents

Abstract

From the initial material which can be processed plastically, the shaping | molding process of the wheel which an annular rim part protrudes in the peripheral edge of a disk part is simplified. The initial material is pressed by a pair of molds 301 and 302, and the protruding material which protrudes from the boundary of these molds is molded into the rim by a roll unit.

Description

Forming method of wheel

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming various wheels in which a disk portion and a rim portion around the edge are integrated from a material rich in plastic processability such as an aluminum alloy or a magnesium alloy.

(Prior Art and Challenge)

In wheels such as automobile wheels and pulleys for belt transmission, a rim portion projecting in a direction perpendicular to the disk portion is integrally formed on the outer circumference of the disk portion. In a wheel for an automobile, a disc shaped disc having an annular wall protruding at a peripheral edge thereof is formed at one end, and the annular wall is formed in the drop center portion 23 and the interior as shown in FIGS. 1A and 1B. It is molded into a rim section consisting of a rim 24 and an outer rim 22. In the latter pulley, after being formed into a plate-shaped body, the annular wall is finished to a rim portion that becomes a belt hook portion. The plate-shaped body is usually molded by forging, but is formed into a plate-shaped body through a plurality of forging steps from a light alloy block-like material or a disk-shaped material (hereinafter referred to as an initial material). For example, in the conventional method disclosed in Japanese Patent Application Laid-Open No. 3-2574, a plate-shaped body in which a portion other than the annular wall is formed into a final shape is produced by forging, and then the annular wall is subjected to roll forming after the forging. By the rim section.

In the conventional method of forming the annular wall, the forging pressure when forming the plate-shaped body from the initial material is extremely large, because the plate-shaped body has a shape in which the annular wall protrudes from the circumferential edge of the disc portion at right angles. Therefore, in the forging process, the initial material must be stretched so as to bend from the bottom portion to the annular wall in the molding die, and when it is reduced, it must be spread and stretched. This is because the transfer resistance is large. Therefore, if the initial material is to be formed into a plate-like body in one forging process, it is inevitable that the forging die is also inevitably large in order to make the forging pressure generating device and the forging device large and at the same time able to withstand the forging pressure. This is not good. Therefore, conventionally, the forging step is divided into a plurality of steps in order to reduce the pressure for forging. In this case, since the total fuel ratio in each forging process becomes small, forging pressure in each process is reduced and a forging apparatus is miniaturized. By the way, in this case, since it is shape | molded by a plate-like object via several process, its productivity is bad. This is because the molds for each process are required, and the time required for forming the plate-shaped body from the initial material is long, and it is necessary to transfer the temporal loss or the workpiece to each process. Therefore, the time required for the whole process of forming the wheel with the rim on the circumferential edge of the disk part from the initial material is naturally long, and the productivity of the pit is poor. The present invention has been made in view of this point, and in the "method of forming the wheel which protrudes the rim part from the circumferential edge of a disk part in the axial direction from a material which can be plastic-processed," the process from the initial material to the wheel is molded. The task is to make it simple, shorten the molding time and reduce the number of molds used.

(Technical means)

The technical means of the present invention for solving the above problems is "pressing the initial material 10 in the axial direction by a pair of mutually opposing molds (301, 302) to form a disk portion and at the same time the initial material accompanying the pressing The protruding material protruding from the circumferential edge of these molds by the leading edge of (10) is molded into the rim portion by the roller units rotating relative to the two molds.

1 (a) and (b) are cross-sectional views of a wheel in which the rim portion and the disc portion are integrated,

2 is a cross-sectional view of a device used to practice the method of the present invention,

3 is an explanatory view of arrangement of the first roller device 41 to the third roller device 43,

4 is an explanatory view of the initial forming process of the wheel,

5 is a cross-sectional view of the molding completed state,

6 is an explanatory diagram of a cross-sectional forming process of the rim 2,

7 is a cross-sectional view in the case where the central opening of the disk unit 1 forms a large wheel,

8 is an explanatory diagram of another molding apparatus for carrying out the present invention;

9 is an explanatory diagram in the case of forming the V-belt pulley in one step;

10 is an explanatory diagram when forming a flat belt pulley in one step;

11 is an explanatory diagram in the case where the decoupling step and the outer rim forming step are one step;

The twelfth part is an explanatory diagram of a method of forming a wheel (plate-shaped body) in which an annular bent piece 90 protrudes at the circumferential edge of the disc 1;

13 is an explanatory diagram in the case of opening the annular curved piece 90 of the plate-shaped body,

14 is an explanatory diagram of the decadal trajectory in the decoupling step;

FIG. 15 is an explanatory diagram of a step of opening the annular curved piece 90 of the plate-shaped body;

FIG. 16 is an explanatory diagram of another method of simultaneously performing a decoupling step and an outer rim forming step in Example 1. FIG.

* Explanation of symbols for main parts of the drawings

1: disk unit 301, 302: mold

10: initial material 81, 83 to 85: processing roller

2: rim 401: ten

The technical means act as follows.

The initial material 10 is interposed between the molds 301 and 302 and is extended by pressing these mold mutually in the axial direction. As this pressurization progresses, the raw material which comprises the initial material 10 protrudes outward from the boundary part of a metal mold | die. The protruding material is formed into a rim portion projecting in a direction perpendicular to the disk portion 1 by the roller units which rotate relative to the two molds. That is, when the pair of molds 301 and 302 rotate, the roller unit moves in the radial direction or the axial direction of the mold at its outer circumference or is fixed at a fixed position to perform the molding. On the contrary, when the pair of molds 301 and 302 do not rotate, the roller unit turns around the outer periphery of the mold and the molding is performed. When forming the rim, the pressing force acting between the molds 301 and 302 may be relatively small. Since the annular protruding material protruding from the pair of mold boundary portions is only in contact with the roller unit, the entire circumferential edge of the entire edge of the material is bent in the molding die as in the case of molding with wheels by forging. This is because the leading resistance of the material is greatly reduced as compared with the case of contact with the end face.

Since the process from the initial material 10 to the rim portion is formed at the circumferential edge of the disk part is one or a series of processes using a pair of molds (301, 302) from the initial material 10 compared to the conventional processing method The processing time for forming the wheel can be shortened, and the number of required molds is also reduced. Therefore, its productivity is much improved compared with employing the conventional method, and the wheels are manufactured at low cost.

(Example)

Next, embodiments of the present invention described above will be described in detail with reference to the drawings.

(Example 1)

In the present embodiment, a wheel for an automobile in which the disk portion 1 and the rim portion 2 as shown in FIG. As the apparatus for this purpose, as shown in FIG. 2, the lower fixed mold 301 and the upper movable mold 302 faced up and down are employed, and the mold 302 is driven up and down. First forming rollers for forming the decoupling roller 401 for decoupling and the entire outer rim 22 from the outer rim side of the drop center 23 on the rim end face at three outer peripheries of these molds ( 402, and a second forming roller 403 for forming the whole of the inner rim 24 from the inner rim side of the drop center 23 are arranged to be movable. Here, these rollers correspond to the roller units for shape | molding the protruding material in this invention. The die 302 is supported by the support 5, and the die 302 is pressed in a direction opposite to the axis of the die 301. For this reason, this support body 5 is provided in series with the output shaft of the hydraulic apparatus 52 provided in the deck 51 at the upper end of the frame 50 of an apparatus, and is driven up and down by this hydraulic apparatus 52. As shown in FIG. The upper surface of the metal mold 301 is the first pressing surface 31, and is molded in the same manner as the surface shape of the outer surface of the disk 1. Since the uneven pattern part is formed in the outer surface of the disk part 1, this 1st pressing surface 31 becomes the uneven surface corresponded with the said uneven pattern part. Moreover, the trunk | drum 32 which continues to the outer periphery of this 1st press surface 31 is the inner peripheral surface of the outer rim 22, and this from a part of drop center 23 of FIG. It has a cross-sectional shape adapted to the outer side surface following. On the other hand, the mold 302 also has a second pressing surface 33 whose lower surface corresponds to the inner surface shape of the disk portion 1, and the cross-sectional shape of the trunk portion 34 of the mold 302 is a drop center ( It is set to match the cross-sectional shape from a part of 23) to the inner circumferential surface and the outer surface of the inner rim 24. As shown in FIG. 3, the said three roller apparatuses are arrange | positioned in the position which divided the circumference into three at the side of the boundary part of the said metal mold 301 and the metal mold 302. As shown in FIG. These roller devices are arranged on the upper surface of the annular rotary bed 62 concentrically installed with the fixed bed 61 to which the mold 301 is fixed, and the first roller having a ten roller 401 in the figure. In the fixed bed 61, a third roller device 43 having a device 41, a second roller device 42 having a first shaping roller 402, and a second roller having a second shaping roller 403, It is arranged in this order in the counterclockwise direction of the figure. Each roller device has a support for supporting the rollers to be movable both in the radial direction and in the upward direction. In particular, the support of the third roller device 43 has the posture of the second forming roller 403 in addition to the movement in the two directions. The rotation direction is also movable to change. Each said support part is a structure controlled by hydraulic drive. For this reason, the lower part of the rotating bed 62 is equipped with the hydraulic circuit connection device free of relative rotation. In this embodiment, as the connecting device, a groove portion communicating with a hydraulic circuit to each roller body is formed on the lower outer periphery of the rotary bed 62, and an annular connector 63 having a groove portion on the inlet side facing each groove portion is provided. ) Is fitted in the concentric state with the rotary bed and fixed. Here, since the appropriate sealing means is fitted between the connector 63 and the outer circumferential surface of the rotary bed 62, no leakage from each hydraulic circuit occurs even when they are rotated relative to each other. The hydraulic connector 65 is connected to the connector 63 via the control valve unit 64 from the hydraulic pressure source 65. The control valve unit is provided with a plurality of control valves for separately controlling each hydraulic circuit, these control valves are separately controlled by an output of a microcomputer, etc., and control the position of each roller device support unit described above. The posture of the second forming roller 403 is controlled. The rotating bed 62 is supported by the fixed bed 61 in a rotational manner, and is provided with a bevel gear mounted on the upper portion of the rotating bed 62 and a bevel gear provided on the output shaft of the reduction gear 67 that is driven with the driving motor 66. Is interlocking. The actuality of the method of manufacturing the final wheel from the initial material 10 using the above apparatus will be described based on FIGS. 2 to 6. In the method of the present embodiment, as shown in Fig. 2, the cylindrical initial material 10 is inserted between the molds 301 and 302, and then the mold 302 is driven down by the output of the hydraulic device 52. The initial material 10 is pressed by the molds 301 and 302. As pressurization progresses, as shown in FIGS. 4-5, the initial material 10 is shape | molded in the shape which imitated on the 1st press surface 31 and the 2nd press surface 33, and the leading edge accompanying this pressurization. By this, the surplus material becomes a protruding material and is pushed out from the boundary of the molds 301 and 302. At this time, the rotary bed 62 is in a rotational driving state, the decay roller 401 is moved to the protruding material side. The outer circumferential surface of the decal roller 401 has a pair of arc-shaped cross-sections 44 and 45 that extend upward or downward, and the edges of the boundary of the arc-shaped cross-sections 44 and 45 are relative to the protruding material. It is press-fitted by. Since the rotatable rollers 401 are supported by the support part in a rotational manner, they are rotated relative to the protruding material by the rotation of the rotary bed 62, so that the protruding materials protruding from the boundary portions of the molds 301 and 302 are protruded. As it expands, it decomposes into two parts. At the time when the mold 302 drops to the strongest position, the initial material 10 is formed between the first pressing surface 31 and the second pressing surface 33 between the molds 301 and 302 as shown in FIG. Part of the outer rim side of the drop center 23, the outer rim equivalent portion 25 corresponding to the outer rim 22, and the inner rim side of the drop center 23 at the circumferential edge of the disk portion 1 imitating the surface shape. An annular curved piece composed of a portion of the inner rim corresponding to the inner rim 24 and the inner rim 24 is formed as a wheel finished product. When this decoupling process is completed, the decoupling roller 401 is retracted, and then, as shown in FIG. 6, the first forming roller 402 is expanded toward the outer rim equivalent portion 25, so that a part of the drop center 23 and the external lining ( 22) is molded. In this embodiment, since the shape of the outer circumferential surface of the first forming roller 402 is adapted to the shape of the portion from the part of the drop center 23 to the outer circumferential surface of the outer rim 22, the body of the mold 301 Since the negative shape corresponds to the shape of the inner circumferential surface and the outer surface of the outer rim 22 side of the rim part 2, when the depressed roller 401 is press-fitted to a predetermined position, a part of the drop center 23 of the rim part 2 is pressed. The cross section of the outer rim 22 is molded from this. At the same time as the forming process of the cross section on the outer rim 22 side or after the completion of this process, as shown in the same figure, the second forming roller 403 abuts against the inner rim equivalent portion 26. In this embodiment, the third roller device 43 including the second shaping roller 403 is used as the spinning roller device, and the inner rim equivalent portion 26 is controlled while controlling the posture of the second shaping roller 403. Spinning is performed to form a cross-sectional shape imitating the trunk portion 34 of the mold 302. As a result, a part of the drop center 23 and the inner rim 24 are formed. Thereafter, the second molding roller 403 is returned and moved to the outside of the molded rim 2. When each of the above steps is completed, the wheel in which the disc portion 1 and the rim portion 2 are integrated is molded. In this embodiment, the plate 69 whose output shaft of the knockout device 68 mounted on the fixed bed 61 passes through the mold 301 and coincides with the surface shape of the central portion of the outer surface of the disk portion 1 at the tip thereof. Since it melt | dissolves and operates the apparatus 68 and protrudes the output shaft, the wheel after completion | finish of molding is taken out to the upper side of the metal mold | die 301. Thereafter, the wheel is taken out from the apparatus of the above embodiment to remove the finish or burr, finish cutting or polishing thereon, and the wheel for the automobile is completed. When the knockout device 68 is returned to return the plate 69 to the mold 301 and the above series of steps are repeated, the wheels are continuously manufactured. In addition, in the method of the above embodiment, it goes without saying that the volume of the initial material 10 should be matched to the volume of the product wheel. In addition, since the decal roller 401 can be moved horizontally and vertically in the decoupling process by the decoupling roller 401, when the decoupling roller is opened as shown in FIGS. 4 to 5, the decoupling position is adjusted in accordance with the volume ratio of the inner rim and the outer rim. Move up and down. Thereby, even if the cross-sectional length of the outer rim correspondence part 25 and the inner rim correspondence part 26 after ten opening is the same, the thickness will differ. Therefore, by setting the inner rim equivalent portion 26 thicker than the outer rim equivalent portion 25 by the above control, the volume ratio of the outer rim equivalent portion 25 and the inner rim equivalent portion 26 is appropriately set. . In the above embodiment, the disc part 1 is formed to have a shape corresponding to the disc part of the wheel. It is also possible to mold in the form having only the rim flange 21 for coupling. In this case, the first pressing surface 31 coincides with the outer surface of the rim flange 21, and the second pressing surface 33 coincides with the inner surface of the rim flange 21. Then, in the state where the mold 302 is dropped to the strongest position, the portion of the disc portion 1 corresponding to the rim flange 21 is continuous on the outer circumference of the thinner cutting portion 93 as shown in FIG. . In this case, a rim in which only the rim 2 and the rim flange 21 are integrated is molded by the above apparatus. In addition, the cutout portion 93 is removed by punching after molding of the rim portion by the above method. Further, at the time of this punching, a plurality of bolt holes are formed in the rim flange 21 at a predetermined pitch. This rim is screwed with the outer periphery of the separately produced disk 1 to form a wheel for an automobile.

(Example 2)

In the above embodiment, the roller devices are fixed so that the roller devices rotate around the outer circumference, so that the rollers are fixed to rotate the workpiece and the molds 301, 302 and the roller devices relative to each other. The molds 301 and 302 can be synchronously rotated. For example, the apparatus shown in FIG. 8 is employed. In the present embodiment, as shown in the figure, the mold 301 is suspended from the deck 51 at the upper end of the frame 50, and the mold 302 is supported by the lower fixed bed 61. have. The mold 301 is attached to the lower surface of the mold mounting stand 59 in the downwardly open cylindrical holder 57 suspended from the deck 51. The cylindrical holder 57 is attached to the output shaft of the hydraulic device 52 disposed on the upper surface of the deck 51, and a pair of guide posts protruding from the upper surface of the cylindrical holder 57 has a deck 51. Penetrate The cylinder is held by a cylindrical holder 57 and freely rotated therethrough, and is provided with a worm gear device including a worm wheel 58 formed on the outer circumferential surface of the body and a worm 53 embedded in the cylindrical holder 57. It is made to drive with the output shaft 54 of the drive motor (not shown) provided in the holder 57 of a shape. Accordingly, the mold 301 is driven to rotate by the rotation of the drive motor, and is driven up and down by the hydraulic device 52. The mold 302 is attached to the upper surface of the mold mounting table 501 embedded in the holder 65 attached to the fixed bed 61, and the mold mounting table 501 is a rotation driving device of the mold 301. It is rotated by a driving motor (not shown) through the same worm gear device as the motor. Further, a first roller device 41 provided with a ten roller 401 is provided on one side plate of the frame 50, and is driven in a horizontal direction while being driven up and down by hydraulic driving. On the other side plate of the frame 50, the roller apparatus 7 provided with the shaping roller 40 is arrange | positioned. This apparatus also drives the forming roller 40 in the horizontal direction and the vertical direction by hydraulic driving, and also controls the attitude of the forming roller. This roller apparatus is a well-known spinning roller apparatus. In order to implement the method of the present invention using the above apparatus, the hydraulic device 52 is driven while the initial material 10 is interposed between the molds 301 and 302 to lower the mold 301 and the molds 301 and 302. The initial material 10 is pressurized and extended so that the protruding material is opened by the first roller device 41. Then, the end surface of each part of the rim part 2 is shape | molded by the spinning roller process by the said roller device 7. In addition, the following modifications to the structure of the present invention are possible.

(1) In the above embodiment, the wheel for automobiles has been described as an example, but it can be carried out by a method for manufacturing wheels used as other light vehicle wheels or pulleys. In this case, as shown in FIG. 9, the final cross-sectional shape of the rim part 2 is shape | molded using the processing roller 81 provided with the ten roller part 48 and the shaping roller part 49. As shown in FIG. In particular, in the case of the V-belt pulley as shown in the same figure, since the outer rim 22 and the inner rim 24 constituting the rim 2 are symmetrical, the molding is further facilitated. In this case, by the rim end surface, it is not necessary to provide the processing roller 81 with the ten roller parts 48 which consist of convex parts like the same figure. Moreover, in the case of the pulley for flat belts, as shown in FIG. 10, the processing roller device is made into the cylindrical roller 82, and the shape of the trunk | drum of the metal mold | die 301, 302 which opposes this is a belt hook part (rim part) of the pulley. Match the shape of the inner circumferential surface of As a result, the protruding material becomes a rim portion 2 corresponding to the flat belt hanger, thereby completing a pulley for a flat belt. In these cases, both of the ends and the processing rollers 81 or the cylindrical rollers are formed at the inner circumferential surfaces of the rim portions of the trunk portions 301 and 302 of the pair of molds 301 and 302 at the time of completion of or before the rim portion molding. Make sure both ends of 82 are aligned. In this case, the lower end of the mold 302 and the processing roller 81 or the cylindrical roller 82 rotating at a constant height are fixed in contact with the lower body of the lower portion of the rim inner peripheral surface of the mold. As shown by the imaginary line of the drawing, when the upper movable mold 301 is in a non-pressurized state, it is separated from the processing roller 81 or the cylindrical roller 82, but the disk portion 1 It is also possible to make contact with the upper end of the processing roller 81 or the cylindrical roller 82 as shown by the solid line of the figure at the completion of the molding. This molding method is also used for manufacturing automobile wheels. In this case, the shape of the rim inner peripheral surface forming portion of the trunk portion of the molds 301 and 302 is matched to that of the automobile wheel, and the processing roller 81 is made to match the shape of the outer peripheral surface of the rim portion of the automobile wheel.

② In the roller unit according to the first embodiment, the first roller device 41 having the decal roller 401 and the second roller device 42 having the first shaping roller 402 are separately installed, but the rim portion is provided. When the eccentricity of the disc part 1 with respect to (2) is large, ie, when the width | variety of the outer rim 22 is small, the said two roller apparatus may be made into one roller apparatus. In this case, for example, if the roller roller 49 is press-molded using the processing roller 83 in which the molding roller portion 49 and the decoupling roller portion 48 are coaxially integrated together, the processing roller as shown in FIG. The material opened by the decoupling roller portion of (83) is finally molded by the forming roller portion 49 to a range of the outer rim 22 of the rim portion 2 and a part of the drop center 23 subsequent thereto. do.

(3) In Examples 1 and 2, the protruding material is opened to form the rim 2, but the annular bending piece 90 protrudes only on one side of the disk 1 from the rim 2. In this case, as the roller unit, as shown in FIG. 12, it is only necessary to use the processing roller 84 having the arcuate cross-section 45 on one side. Then, when the working roller 84 is pushed onto the protruding material as shown in the figure, the dies 301 and 302 are bent upwards as the pressure of the molds 301 and 302 proceeds, and finally, one side of the disc 1 is annular. The bent piece 90 protrudes. Depending on the type of wheel, even this molding may be a product wheel, but the annular bent piece may be further processed into an automobile wheel as shown in the first and second embodiments. In this case, the annular bending piece 90 is formed into a continuous plate-like body at the edge of the disc 1, and then the decal roller 401 is used as shown in FIGS. 13 to 15. The outer rim is located on the outer rim side of the disk 1 and the inner rim is located on the opposite side of the disk 1, and then each part after the opening is processed to the rim section in the same manner as in the first embodiment. At this time, as shown in FIG. 14, the deciphering path 92 is set in accordance with the volume distribution between the inner rim side and the outer rim side.

(4) The method shown in Fig. 16 can also be employed as a method of simultaneously performing the decoupling process and the forming process of the outer rim. In this case, the relative position in the radial and axial directions with the mold 301 and the processing roller 85 having the upper portion of the trunk portion formed from the drop center portion of the rim portion 2 to the outer rim 22 is set constant. In this case, the lower end shaft portion of the processing roller 85 is brought into contact with the lower edge of the mold 301 in the rolling contact state. The processing roller 85 includes a forming roller portion 491 matching the cross-sectional shape of the outer circumferential surface of the rim portion from the drop center portion to the outer rim 22, the leading roller portion 492 having an arc shape in cross section, and ten of these boundaries. The roller part 493 is comprised, and this ten roller part 493 is set in the state matched with the said drop center part. Then, the mold 302 having a shape corresponding to the inner rim 24 from the drop center portion of the rim 2 is placed on the upper side of the mold 301 so that the pair of molds 301 and 302 are disposed. The protruding material from the molds 301 and 302 is molded by the processing roller 85 by joining and extending the initial material by making the mold 302 strong while rotating synchronously. At this time, the outer rim side is press-opened by the decoupling roller portion 493, and is completed by the outer rim 22 at the completion of molding of the disk portion 1. On the other mold 302 side, the inner rim side after the opening passes between the leading edge roller portion 492 and the trunk portion of the mold 302 and is extended as shown in FIG. ). This inner rim equivalent 26 is suitably molded into the outer rim 24 in the same manner as in the above-described embodiment by roll forming.

Claims (12)

In the method of forming the wheel which protrudes the rim part axially from the peripheral part of a disc part from a plastic processable material, it presses the initial material 10 in an axial direction by a pair of metal mold | die 301 and 302 which oppose each other. At the same time as forming the disk portion, the protruding material protruding from the boundary of the peripheral edges of these molds by the leading edge of the initial material 10 in accordance with the pressing to form the rim portion by the roller unit rotating relative to the two molds. Forming method of the wheel 2. The roller unit according to claim 1, wherein a predetermined range on the opposite end surface side of the trunk portion of the pair of molds 301 and 302 is a rim portion inner circumferential surface forming portion that mimics the rim inner circumference, and the pair of molds 301 and 302 are rotated to the roller unit. The molding method of the wheel, characterized in that for molding the rim. 3. The rim part forming process by the roller unit according to claim 2, wherein the rim part forming step comprises a forming step by a processing roller having a decoy roller part 48 and a forming roller part 49 subsequent thereto, and in the forming step, the processing roller. And the relative positions in the axial direction and the radial direction with respect to one of the molds 301 and 302 are set to be constant, and are surrounded by the busbar of the trunk portion of the mold and the busbar of the molding roller part 49. The shape of the sinusoidal molding space coincides with the cross-sectional shape of the outer rim or the inner rim of the finished rim, and the protrusion material is opened to the outer rim side and the inner rim side by the decoupling roller portion 48, so that one side of the protruding material after the opening is opened. The molding method of a wheel, characterized in that the cross-sectional shape of the outer rim or the inner rim is pressed into the molding space. 3. The rim portion forming process by the roller unit is a forming process by a processing roller having a forming roller portion 49 corresponding to the outer circumferential surface of the rim portion, wherein the processing roller and the mold (301, 302) are formed. The relative position in the axial direction and the radial direction with respect to one of the molds is set to be constant so that the bus bar of the trunk portion of the trunk portion of the pair of molds 301 and 302 and the forming roller portion 49 in the disk portion forming completed state are fixed. And the shape of the molding space surrounded by the shape of the rim is matched to the cross-sectional shape of the rim, and the protruding material is pressed into the molding space so that the rim section shape is formed. 5. The method for forming a wheel according to claim 4, wherein the processing roller is a cylindrical roller perpendicular to the protruding material, and the outer circumferential surface of the rim is molded on the circumferential surface. The process of claim 2, wherein the forming of the protruding material into the rim by the roller unit comprises a decoupling step of decomposing the protruding material generated along the leading edge into the outer rim side and the inner rim side, and each part formed by the decoupling step into the rim end surface. A method of forming a wheel, comprising the step of forming a roll. 7. The method for forming a wheel according to claim 6, wherein the deforming step and the step formed by the decoupling step are carried out simultaneously with the step of roll forming the rim section. 3. The process of claim 2, wherein the step of forming the protruding material into the rim by the roller unit is a step of bending the protruding material produced along the leading edge to the torso side of one mold to form an annular curved piece, and after the end edge stopping. And the step of opening the annular bent piece to the outer rim side positioned on the outer side of the disc portion and the inner rim side positioned on the opposite side thereof, and to roll forming the corner portions formed by the opening process to the rim section. Method for forming a wheel, characterized in that. 7. The process according to claim 6, wherein the decoupling process and the forming process of the outer rim 22 are simultaneously performed using a processing roller having a decoupling roller portion 48 and a forming roller portion 49 for forming the outer rim 22. Forming method of the wheel, characterized in that. 9. The process according to claim 8, wherein the decoupling process and the forming process of the outer rim 22 are simultaneously performed using a processing roller having a decoupling roller portion 48 and a forming roller portion 49 for forming the outer rim 22. Forming method of the wheel, characterized in that. 10. The mold according to claim 7, wherein the molding roller is provided between the mold roller 301 and the mold 302 and / or the mold roller 302 and / or the mold 302 with a molding roller portion for rim molding. And a method of forming a wheel, wherein the opened protruding material is press-fitted. 3. The method for forming a wheel according to claim 2, wherein the disc portion is provided with only an annular rim flange extending on the inner circumferential side of the rim.